00195982-03_SM_SWS_EN.pdf - 第47页
3 SIPLACE wafer system (SWS) function 3.1 SWS basic functions Service Manual SIPLACE Wafer System (SWS) 11/2018 47 3 SIPLACE wafer system (SWS) function The new SWS provides a fully automatic wafer and chip handling syst…
2 Overview of the SIPLACE wafer system (SWS)
2.4 Description of SWS assemblies
46 Service Manual SIPLACE Wafer System (SWS) 11/2018
Description
While picking dies from a wafer, there is a danger that the die could begin to tilt. This can be
caused by an irregular adhesion of the die on the foil or an eccentric positioning of the needle. In
the case of dies which are positioned closely to one another, the neighboring die could be touched
and mutual damage can not be ruled out.
To prevent this, the wafer foil is stretched before the die is picked. This increases the distances
between the dies on the foil and makes it possible to pick dies without risks. The larger distances
between the dies also makes it easier for the Vision system to recognize them.
After the downholder plate has moved up and the clamp has been opened, the wafer foil sags. A
wafer with a sagging foil can not be moved back into the magazine.
Once the clamp and the downholder plate have been opened, the stretched wafer foil is warmed up
by the heater module. This shrinks the wafer foil (sag less than 9 mm) so that it can be moved back
into the magazine.
Fig.27: SIPLACE SWS wafer stretcher with stretched wafer foil
1. Stretched wafer foil in the SIPLACE SWS wafer stretcher
See also
2 12.1 "Explanation of the wafer stretcher" [}265]
3 SIPLACE wafer system (SWS) function
3.1 SWS basic functions
Service Manual SIPLACE Wafer System (SWS) 11/2018 47
3 SIPLACE wafer system (SWS) function
The new SWS provides a fully automatic wafer and chip handling system. It is fully integrated into a
SIPLACE CA placement system location. Each location can (with restrictions) be fitted with an
SWS or with an X table.
The SWS functions like a feeder for the SIPLACE system and transports the dies from the wafer to
a single, fixed pickup position for the placement head. The placement head picks the die up from
the SWS and places this on the board as done during SMD handling.
The SWS appears in SIPLACE Pro like an X table with a special feeder type. The programming of
the SIPLACE system is the same, for example, as that for the SIPLACE X-Series. Die handling is
programmed at a separate terminal on the SWS. The main parameters to be programmed are as
follows:
●
Wafer and die dimensions
●
Magazine type
●
Wafer frame type
●
Die recognition
●
Die ejection parameters
●
Wafer map system
●
Link to component programmed in SIPLACE Pro
3.1 SWS basic functions
The main die handling components are the wafer table, the magazine lift, the ejection system, the
flip unit and the control unit with corresponding SWS software.
The wafer with the relevant die is loaded from the magazine and fixed onto the wafer table. The
wafer table places the die using the ejector system, which releases the die from the wafer foil, and
transfers it to the flip unit. The flip unit rotates the die by 180° and makes this available for pickup
by the placement head.
The SIPLACE CA uses a high precision SIPLACE placement head which has been specifically se-
lected for maximum accuracy, to fulfill the specifications of 35µm at 3sigma for normal conditions
and 25µm at 3sigma under restricted conditions.
NOTICE
All movable positioning axes in the SWS are servo axes!
The following options are available to support the whole range of process-oriented functions:
●
Wafer map system
●
Linear dipping unit
●
Die attach unit
●
Small die kit (on request)
●
Barcode scanner
●
Wafer expander
●
Inspection camera
3 SIPLACE wafer system (SWS) function
3.2 Basic die presentation process
48 Service Manual SIPLACE Wafer System (SWS) 11/2018
3.2 Basic die presentation process
The basic die presentation process supported by the SWS can be divided into three main steps:
●
Die recognition and positioning for ejection (incl. inkspot recognition or wafer map)
●
Ejection procedure
●
Pickup procedure for die attach or flip chip processing.
Fig.28: Basic die presentation process
There are two main ways to place dies, the flip chip and the die attach process.